THERAPY FOR BACTERIAL CONJUNCTIVITIS

Bacterial conjunctivitis is most often a self-limited disease. Most cases are successfully treated with a topical antibiotic agent. Treatment is indicated to shorten the disease course and reduce contagious spread. Therapy is usually empiric, requiring an understanding of the likely pathogens in a given patient population. There are unusual situations, however, in which conjunctival cultures should be performed and those in which systemic therapy is required. Conjunctivitis occurs when pathogenic bacteria overwhelm conjunctival defenses, resulting in inflammation. Organisms causing conjunctivitis may be components of the normal lid flora (e.g., Staphylococcus aureus ) or nasopharyngeal flora (e.g., Hemophilus influenzae ), or may be introduced by hand or aerosolized contact. The degree of inflammation, discharge, and symptoms vary. Most cases, up to 80%, become bilateral, justifying bilateral treatment even when presenting unilaterally. 42 A typical case of conjunctivitis may be symptomatic for 8 days if left untreated, as opposed to only 4 days with treatment. 12 Thus, treatment with topical agents is indicated usually within only 4 days of symptom onset. 21 Acute conjunctivitis is defined by onset within 3 weeks of presentation. Hyperpurulent conjunctivitis manifests with profuse purulence, lid edema, chemosis, and subconjunctival hemorrhages. Neisseria gonorrhoeae and Neisseria meningitidis classically cause hyperpurulent conjunctivitis, though Streptococcus and Staphylococcus species may be causative. 22 Streptococcus pyogenes and Corynebacterium diphtheriae can cause an acute membranous conjunctivitis. 38 Chronic conjunctivitis is defined by persistence for at least 3 weeks. Chronic conjunctivitis is frequently caused by Staphylococcus aureus or Moraxella lacunata, and is often related to continued bacterial exposure from blepharitis or dacryocystitis. 38